1. Field of the Invention
The invention relates to a retaining device for utility vehicles, such as fork-lift trucks, tractors, construction and agricultural machines and public utility vehicles, with a canopy protecting the driver or operator from falling out of the vehicle while overturning. The roof or canopy has front and rear struts, and is at firstxe2x80x94without the novel retaining devicexe2x80x94open to the sides.
The invented retaining device is qualified to absorb centrifugal forces up to 1400 Newton proved in various tests in a research project from the Gerhard-Mercator-University Duisburg, Germany, Faculty Mechanical Engineering, subject group product engineering. These forces are usually experienced during narrow curves in which the most accidents according to the German compulsory casualty insurances occurs. Standard canopies do not protect from these forces.
To reach this target the novel retaining system which is attached between front and rear struts on the driver""s open side protect exactly three important body points of the driver or operator: the Shoulder-Point, the Hip-Point, and the Knee-Point (see FIG. 2).
Furthermore this retaining system is especially designed for retrofitting all canopy guards based on the SRP (seat reference point) of the driver seat and 5 configuration parameters.
2. Background of the Invention
With increasing numbers of accidents with fork lift trucks outfitted only with canopies which are usually open on their sides, it was obviously urgent to take appropriate action in order to reduce these accidents with the invention of an effective retaining device which prevents a lateral falling out by overturning of a vehicle or by speeding up in curves. A retaining system is needed which combines all following advantages: a) Low cost b) easy in construction c) easy and quick to refit d) with a high acceptance to the driver and e) with a guarantee of a maximum liberty of action for the driver leaning forward and outward or slewing while shunting the vehicle.
The retaining device of the invention is particular for vehicles with no cabs and no doors, such as vehicles with overhead guards which are open to all sides though they have a frame. The invention differs from those patents which guarantee driver""s protection with a complex roll protective frame or a complex, elaborate and expensive door and cab arrangement is the combination of the advantages a) to e) described above.
Seat integrated and other indoor retaining systems like safety-belts restrict the necessary liberty of action and the driver""s acceptance.
3. The Prior Art
The usual retaining systems of utility vehicles are either steel doors or seat belts or bows mounted at suitable fastening sites inside the vehicle. The important difference and also drawback of most of these prior art seat-belt-systems is that belts or bows have to be put on and locked, which is time-consuming and uncomfortable for the driver. This, however, is not done in many cases when driver or operator are necessarily frequently boarding and leaving the vehicle while shunting and ranking. Another significant difference is that special fastening points are required for installing seat belts, which in turn requires changes in the construction of the engine hood.
The present invention does not need special fastening points. It can be mounted easily between the rear and front struts without changing any construction of the frame. In a further difference, safety belts are primarily constructions to prevent falling into the front and not to prevent falling out like the invented novel system. And in contrast to all other retaining systems with automatically locking seat bows or complex steel doors, the novel invented retaining system guarantees the driver a maximum freedom of movement and a maximum view and visibility. A safety belt or safety bow retains the driver on the seat.
This invention is especially for vehicles with no cabs and no doors such as vehicles with overhead guards which are open to all sides though they have a frame. This is an important difference from U.S. Pat. Nos. 3,841,430 and 4,079,985. These patents guarantee the protection with a complex roll protective frame and cab arrangement, missing the combination of the advantages described above.
The thin tube of the door construction in U.S. Pat. No. 5,529,369 is used as support and mounting for a door construction which provides more comfort against weather and rain in opposition to the normally open-air carts without the intention of giving a maximum liberty of action for the driver. Furthermore compared to FIG. 2 it can be seen that the SRP (seat reference point) of this patent is behind the door construction, and therefore the protection against centrifugal forces is not an intention of the patent.
This invention is qualified to catch (intercept, absorb) centrifugal force up to 1400 Newton proved in various tests in a research project from the Gerhard-Mercator-University Duisburg, Germany, Faculty Mechanical Engineering, subject group product engineering.
A door or a cabin separate into xe2x80x9cinsidexe2x80x9d and xe2x80x9coutsidexe2x80x9d. The invented novel retaining system integrates these two spaces, so that it is not necessary for the driver to open the door during a risky maneuver. The driver""s body is free from a safety system such as DE 43 15 824 and therefore the novel retaining system according to the invention is more acceptable to the driver.
The conceptual advantage over a door is due to the ease of utilization (which means no development is necessary for adaption of a specific forklift truck) and low cost. A door is a more general term for an openable side weather protection and is therefore not necessarily suited for the purpose of this invention.
The retaining system according to the invention is fixed between the rear and front struts. It is a horizontally extending support consisting of two bows, whereby on one strut the support is connected and pivoted with a hinge, and on the other strut linked in a locking system like a snap bolt or a rotary drop lock. In completion of the advantages a) to e) listed above, the present invention is a successful and effective combination to reach driver""s safety and protection because it can be mounted in a simple manner, it reduces drivers""s risk from falling out while centrifugal forces are acting on it and assures simple handling and a high driver""s acceptance.